Diplomats and activists say the real number is much higher – probably well into the hundreds.

Other reports say scores of monks have been arrested after leading the biggest anti-government protests seen in Myanmar in almost two decades,

On Monday the Association of South-East Asian Nations (Asean), of which Myanmar is a member, wrote a letter to Than Shwe expressing the group's "revulsion" at the violent repression of demonstrators.

"The confrontation that is unfolding in Myanmar will have serious implications not just for Myanmar itself, but also for Asean and the whole region," the letter said.

Asean rarely comments on the internal affairs of a fellow member state, but the letter contains unusually forceful language, highlighting international pressure on the group to take a tough stand.

In the letter, Lee Hsien Loong, the prime minister of Singapore, the current Asean chair, urged Myanmar's military rulers to work towards national reconciliation and help Gambari "try to find a way forward".

'Destructionists'

So far international condemnation has had no noticeable impact on the Myanmar's government.